I absolutely want to know whats going on in the back. To the poster who said we have enough to worry about already, well sticking my head in the sand and hoping all on the other side of the door will taken care of is not an option. Professional pilots are capable of multi tasking, with a hijack situation in the cabin rating pretty high on the list of priorities. Real time info is what I need to make the best decisions. Relying on a FA to keep up my SA up should be a secondary of tertiary source. With a knife to his or her neck is not the perspective I want. To the poster who said it will not stop the bad guys from getting onboard, granted but the intent is to provide the flight deck with information after they make their move. It was pointed out that the cameras can be disabled. Quite true and problematic. I know some cameras are quite small and hopefully easily hidden. Hopefully they can be hidden to the point that they will not be found or at least the crew gains some insight before the plug is pulled.